Night Sensitive Lighting
As in many other areas of modern life, realisation is gaining ground in the area of lighting that “more and more” – in this case, outdoors light – is not a sustainable strategy and endangers ecosystems that are the basis of life. The new way of thinking about lighting looks at the acute visual needs that need to be met in an overall context. This is one element of a larger, complex equilibrium, balanced with the non-visual, biological effects of light on humans as well as the impact on the natural environment, animals and plants, and the night sky.
LUMINAIRES THAT CONSIDER THE NIGHT ENVIRONMENT
A new approach to outdoor lighting
Conservationists now give planners and users of lighting clear recommendations, for example, in the form of the “five principles for responsible outdoor lighting” from the International Dark-Sky Association (IDA) and the Illuminating Engineering Society (IES). These are:
Useful – all light should have a clear purpose
Before any outdoor luminaires are installed or replaced, ask: Is this lighting needed? How will lighting affect the surroundings, what impact will it have on the environment and wildlife? Are retroreflective or self-illuminating markings and signs also an option? How can the need for permanently installed outdoor lighting be reduced?
Targeted – light should be directed only to where needed
Well-shielded luminaires that are carefully directed downwards produce less unnecessary stray light.
Low light levels – light should not be brighter than necessary
Wherever possible, normative specifications should not be exceeded. Illuminated surfaces also play a role: some materials reflect more light back into the night sky than others.
Controlled – light should be used only when it is useful
Controls such as timers or motion detectors ensure that light is available when it is needed, dimmed when possible and turned off when not needed.
Light colour – as warm as possible
Limit the amount of shorter wavelength (blue-violet light) to the least amount needed.
Source: https://www.darksky.org/our-work/lighting/lighting-principles/
It is clear that the responsibilities of principals, planners and lighting manufacturers are closely interlinked. Joint efforts are needed to successfully implement these demands without neglecting visual and aesthetic requirements.
